Fluid injection recording system utilizing alternating bias field

ABSTRACT

A fluid injection recording system to inject fluid such as magnetic ink from nozzle means on a paper to record a series of dots. Means such as alternating magnetic bias field is applied to the fluid to oscillate the fluid. An input signal is applied to inject the fluid from the nozzle.

11] 3,739,396 June 12, 1973 FLUID INJECTION RECORDING SYSTEM [56] References Cited UNITEDSTATES PATENTS 2,925,312 2/1960 Hollmann UTILIZING ALTERNATING BIAS FIELD [75] Inventors: Koosuke Harada, Fukuoka; Shinjiro 3,l6l,882 l2/l964 Mullin.............. 3,582,954 6/1971 Skala...........................

Takeuchi, Toda, both of Japan [73] Assignee: Mishima Kosan Co., Ltd.,

gs gfgg g z ggg y Primary ExaminerJoseph W. I-lartary p AttorneyE. F. Wenderoth, John E. Lind, A. Ponack Nov. 15, 1971 and V. M. Creedon [22] Filed:

211 Appl. No.: 198,517

[ 5 7] ABSTRACT A fluid injection recording system to inject fluid such as magnetic ink from nozzlemeans o n a paper to re- [30] Foreign Application Priority Data 45/111459 cord a series of dots. Means such as alternating magm to fi MM mu fl e o.h.. 5 mt e C wk we un fl m E 2 mm .m mm w w m dw D 6 H 2 i w m Sm. m s C M l m. fi

n i .m n bA .wd i CU nflvm m 1 0 5 M5 "07 GM 4 3 c "H .8 ms L l m d td um. 11] 2 8 555 [ll Patented June 12, 1973 I KOOSUKE HARADA and SHINJIRO TAKEUCHI INVENTOR. 3

BY UM I MAJL ATTORNEYS FLUID INJECTION RECORDING SYSTEM UTILIZING ALTERNATING BIAS FIELD BACKGROUND OF THE INVENTION The present invention relates to a fluid injection recording system by recording dots on a paper to describe letters or symbols.

It is known to record a-series of dots on a paper by injecting from a slender nozzle some kinds of liquid such as magnetic ink. However as the nozzle is slender, the liquid apts to become solid as a result of outside conditions. Also it is difficult'for the liquid to flow in the nozzle in response to an input signal since the static friction between the inner wall of the nozzle and the liquid is relatively large.

SUMMARY OF THE INVENTION The present invention provides a new nozzle system to the prevent sticking of the recording liquid to inner wall of the nozzle, by applying an oscillation to the liquid in the nozzle to make displacement in the nozzle and injection from the nozzle easier.

According to a feature of the present invention, first and second coils are wound about a nozzle containing magnetic ink, a DC. current and an AC. high frequency current are applied to the first coil to magnetize the magnetic ink in one direction and further to apply oscillation to the magnetic ink to maintain the magnetic ink in an easily flowable state. Further, an input signal is applied to the second coil which is wound near the injection tip of the nozzle to magnetize the magv netic ink in the reverse direction to expel the magnetic ink which is adjacent the nozzle tip.

According to another feature of the present invention, an alternating current is applied between a nozzle containing'recording fluid and an electrode opposing the nozzle. When the applied alternating charge is sufficiently high, the static electric field produced between the fluid in the tip of the nozzle and the opposing electrode oscillates the fluid to keep the fluid in an easily flowable state. Input direct current voltage is applied between the nozzle and the electrode to charge the fluid in the nozzle to effect the injection of the fluid to the electrode.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows a basic diagram of the first embodiment of the fluid injection recording system utilizing alternating current bias according to the present invention, and

FIG. 2 shows a basic diagram of the second embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT retained in the nozzle by surface tention as the nozzle tip is relatively slender.

A coil 3 is wound about the main body portion of the nozzle 1 which may have a larger diameter than the tip portion of the nozzle. Across the terminals 4 and 5 of the coil 3 direct current and alternating bias current are applied to magnetize the magnetic ink 2 in one direction parallel to the longitudinal axis of the nozzle 1, and further to oscillate the magnetized magnetic ink in the nozzle. By properly selecting the direct current and alternating bias current in voltages and frequency, static and alternating magnetic fields are induced.

Static friction is caused between inner wall of the nozzle 1 and magnetic ink without the alternating bias current applied across the terminals 4 and 5, so that magnetic ink tends to stick to the inner wall of the nozzle. However, by applying the alternating bias current, magnetic ink 2 oscillates in the nozzle so that magnetic ink is maintained in an easily flowable state as dynamic friction which is far less than static friction is applied between the inner wall of the nozzle and the magnetic ink. I

A second coil 6 is wound about near the tip end of the nozze l, and a second direct current is applied across terminals 7 and 8 to induce a magnetic field in the reverse direction induced by the first mentioned direct current applied across the terminals 4 and 5. Thus magnetic ink in tip end of the nozzle 1 is repelled by the reverse magnetic field now induced adjacent the tip itself and is injected from the nozzle to record a dot on a paper relatively moving to the nozzle. Thus, the second direct current applied across the terminals 7 and 8 functions as an injection or recording signal. The input signal can be a pulse or one phase of an alternating current which is synchronized to the paper feeding mechanism.

FIG. 2 shows diagramatically a second embodiment of the present invention. A nozzle 11 which is made of an electric conductive material contains fluid 12 which may preferably be an electric conductive material. An electrode 13 is disposed opposite to the tip end 14 of the nozzle 11. An alternating current is applied across the terminals 15 and 16 to produce a static electric field across the nozzle 11 and the electrode 13 to cause oscillation of fluid 12 at tip end 14 of the nozzle to maintain the fluid in an easily flowable state.

When a high tension input signal is applied across terminals 15 and 16, fluid 12 in the tip end 14 of the nozzle 11 is injected toward the electrode 13. By placing a moving paper not shown between the nozzle 11 and the electrode 13, a series of dots can be recorded on the paper. i

The above described embodiments show basic contructions of the present invention. Other means to oscillate the nozzle or fluid, and means to inject fluid can be easily applied without departing from the present invention.

The shape and material of the nozzles 1 and 11 can be selected as desired. The nozzle can be made of nonconductive material when fluid 12 is conductive. In this case the other end of the terminal 15 is inserted in the fluid 12.

Means to oscillate the fluid, alternating bias magnetic field, alternating bias electric field and mechanical oscillating device can be applied. An alternating bias magnetic field can be effectively adopted when magnetic fluid is used or when a magnetostriction oscillating element is used. An alternating bias electric field, a mechanical oscillating device and a magnetostriction oscillator can be utilized to oscillate fluid whatever the fluid is. When a mechanical oscillating device is used,

care must be taken to prevent excessive vibration of the nozzle tip. The primary object to oscillate the fluid is to maintain the fluid easily flowable state in the nozzle. A polyphase alternating bias magnetic field'is preferably utilized to ensure an easy supply of fluid in the nozzle.

Means to inject the fluid will now be explained. At first, an input signal may be a pulse or one or more cycles of an alternating current according to the desired recording system. In order to inject the fluid by such an input signal, a separating force as described in the first embodiment as well as an attracting force can be applied. To reinforce the input signal, a magnetic field produced by an input signal can be reinforced by a static magnetic field to inject the magnetic ink. The input signal also can be utilized to modulate alternating bias magnetic field, and the modulated signal can be reinforced by a static magnetic field to inject the magnetic fluid from the nozzle. Also, a static magnetic field may be modulated by an input signal, and a modulated magnetic field may be reinforced by an alternating magnetic field to inject fluid from the nozzle. Further, combinations of the above mentioned method may also be utilized. The magnetic field may be replaced by an electric field to effect injection of fluid.

In order to concentrate the injected fluid and to concentrate the electric or magnetic field, a pointed electrode or a magnetic pole piece may be disposed opposite to the nozzle, and the applied electric or magnetic field may be controlled corresponding to the input signal.

In practice a plurality of nozzles may preferably be arranged transverse to the paper feed direction to limit the paper feeding to one direction, thus being easily adaptable to facsimile, teletype and other information devices.

What is claimed is:

1. A fluid injection recording system including at least one nozzle containing recording fluid which contains magnetizable material and which nozzle is adapted to inject the fluid to record on a relatively movable paper as a series of dots, the improvement comprising a first coil wound about the nozzle, a second coil wound about the nozzle, near the tip portion thereof, means to apply direct current to the first coil to magnetize the fluid in one direction, means to apply an alternating bias current to the first coil to oscillate the fluid and to maintain the fluid in an easily flowable I state, and means to apply direct current to the second coil asan input signal to magnetize the fluid in another direction and to repel the fluid in the tip portion of the nozzle to cause injection of the fluid from the nozzle. 

